Polysulfonamide thin-film composite reverse osmosis membranes

A series of polysulfonamide reverse osmosis membranes have been synthesized from the interfacial polycondensation reaction of aqueous 1,6-hexanediamine and 1,5-naphthalenedisulfonyl chloride (NDSC) with different amounts of the crosslinking agent 1,3,6-naphthalenetrisulfonyl chloride (NTSC). For NaCl-water feed solutions, the flux decreased and separation increased with the increased amounts of the crosslinking agent. Using the Kimura-Sourirajan transport equations, the pure water permeability coefficient, A, and solute transport coefficient, DAMK/tau, were determined; ln A versus ln DAMK/tau was linear for all membranes. Scanning electron microscopy was used to monitor the changes in surface morphology as a function of the amount of the crosslinking agent. As the amount of NTSC increased, the surface morphology become more smooth and dense. (C) 1998 Elsevier Science B.V.